Test boring drill bit

ABSTRACT

An apparatus for carrying out a test boring wherein the drilling and sampling operations are carried out in one operation is described. A drilling bit is detachably secured to a modified split-barrel sampler which serves as the bottom member of a drill rod. The shank of bit contains (1) a set screw located in a recessed area of the shank in contact with the sampler and releasable by a turn of the bit, (2) an overriding clutch set to engage the sampler on rotation and (3) an overriding clutch set to engage the sampler on vertical withdrawal, the three elements to operate sequentially. The split-barrel sampler is modified in two ways; (1) the ball of the ball check valve is not present during the drilling operation, but is dropped down the drill pipe at the end of the drilling operation and prior to the sampling operation so that it seats on the base of the check valve whereby the ball check valve becomes constituted and, (2) the vent ports which are normally present in a split-barrel sampler are plugged.

United States Patent Tuccillo Oct. 28, 1975 TEST BORING DRILL BIT 3,830,320 8/1974 Van der Wijden 0. 175/238 76 Inventor: Ral h T cill ll3-B St 't l] g gz svl 6 Primary ExaminerDavid H. Brown l Attorney, Agent, or FirmPhilip T. Paul [22] Filed: Feb. 24, 1975 [21] Appl. No.: 552,239 ABSTRACT Related Application Data An apparatus for carrying out a test boring wherein C f S N 4 the drilling and sampling operations are carried out in lgplmrggfggzgart 0 er. 0. 43,806, Feb. 19, one operation is described A drilling bit is detachably secured to a modified 52 US. Cl. 175/237; 175/20; 175/5 8-, Split-barrel Sampler which Serves a e bottom 175/248 member of a drill rod. The shank of bit contains (1) a 51 Int. c1. E21B 25/00 Set Screw located in a recessed area of the Shank in [58] Field of Search 175/20, 58, 236-239, with the tf f d releasable by a turn of 175/244 249 317 403 the b1t, (2) an overriding clutch set to engage the sampler on rotation and (3) an overriding clutch set to 5 References Cited engage the sampler on vertical withdrawal, the three UNITED STATES PATENTS elements to operate sequentially.

The split-barrel sampler is modified in two ways; (1) 1,909,187 5 1933 Ok h l 1 248 2'170716 8x939 if /58 the ball of the ball check valve is not present during 2,326,435 8/1943 Bynum 175/248 x the drilling Operation, but is pp down the drill 2,330,157 9/1943 Stokes 175/236 x pip at he n f h drilling operation and prior to 2,544,993 3/1951 Jackson 175/238 X the sampling operation so that it seats on the base of 3,047,081 7/1962 Pitcher 175/20 X the check valve whereby the ball check valve becomes 3,136,376 6/ 1964 Robihhky 175/238 X constituted and, (2) the vent ports which are normally 2222 present in a split-barrel sampler are plugged. 3,794,127 2/ 1974 Davis 175/58 4 Claims, 11 Drawing Figures US. Patent Oct. 28, 1975 Sheet 1 of4 3,915,245

US. Patent Oct.28, 1975 Sheet 2 of4 3,915,245

Sheet 3 of 4 3,915,245

US. Patent Oct. 28, 1975 FIG.6

2 liihllilhll J \fl% FIGS FIG?

US. Patent Oct. 28, 1975 FIGIO Sheet 4 of 4 FIG. I l

TEST BORING DRILL BIT CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of Ser. No. 443,806 filed Feb. 19, 1974, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to the art of test borings. Test borings are a necessary preliminary to the construction of buildings, bridges, roads, tunnels etc. The procedures are standardized as ASTM D I586, Penetration Test and Split-Barrel Sampling of Soils" and ASTM D I587, Thin-Walled Tube Sampling of Soils which outline the procedures involved including specific drawings of the split-barrel sampler and of the thinwalled tube sampler. They can be found 1973 Annual Book of ASTM Standards, Library of Congress Catalogue Card No. 40-10712.

Essentially, the procedure involves the following:

1. a test hole is drilled to a desired elevation,

2. the bit is withdrawn and replaced by the sampler,

3. the sampler is lowered to the bottom of the test hole and the sampling made,

4. the sampler containing the sample is brought to the surface and the sample examined. From the examination of the soil and the force required to make the penetration, a profile of the land is obtained.

SUMMARY OF THE INVENTION The primary object of this invention is to provide a means whereby the drilling and sampling operations are combined into one operation, i.e., steps (2) and (3) above are combined. Another object is to provide a means that will ensure that the material to be sampled has not been disturbed by the drilling operation. A still further object is to provide a means of centering the sampler in the hole during the sampling operation.

These objectives may be realized by the use of an earth boring and sampling apparatus which comprises;

a. a tubular coring device of solid wall construction containing,

b. the seat of a ball check valve, and, separate therefrom,

c. a ball to fit the seat of the ball check valve, said coring device being further detachably secured to,

d. a bit centrally and longitudinally apertured to accomodate the coring device, the shank of the bit terminating in cutting teeth which on rotation form a drill circle said shank being in the shape of a cylinder with a flattened side and having,

e. a left handed set screw located in the flattened side engaging the coring device and terminating in a handle which when tightened reaches to the drill circle and is in a position of vertical to right of vertical and is releasable by a turn of the bit,

f. an overriding clutch means engaging the coring device on rotation, and,

g. an overriding clutch means engaging the coring device on vertical movement,

the elements to act in the order (e), (f), (c) on (b) and (g)- Of particular importance in the above apparatus is the bit, the elements of which act on the coring device according to the sequence, (e), (f), and (g).

The drilling of a test hole is normally carried out by the standard rotary method wherein drilling fluid is forced down the drill pipe, through the drill bit where it cools the bit, picks up cuttings and then returns to the surface through the annulus between the drill and the wall of the drilled hole. By removing the ball from the ball check valve of the split-barrel sampler and plugg'ing the vent ports, the split-barrel sampler becomes in effect the bottom segment of the drill pipe since the drilling fluid cannot escape through the vent ports and is forced down through the open check valve to the bottom of the sampler.

To the sampler, the drill bit is detachably secured by the set screw the sole purpose of which is to hold the bit onto the sampler while the assembly is being lowered to drilling elevation.

The flow of drilling fluid is started down the drill pip and drilling commenced. The initial rotation releases the set screw andtransfers the binding to the rotational overriding clutch. When the drilling has gone the desired depth, drilling is stopped and the drilling fluid line disconnected at the top of the drill pipe. The ball is now dropped down the open drill pipe to the sampler where it settles onto the check valve seat. The ball check valve is now constituted.

The sampling is now made by driving the sampler down through the bit, the ball check valve permitting displacement of drilling fluid by the earth as it enters the sampler and also keeping drilling fluid out of the sample.

The whole assembly is then drawn to the surface, the upward movement of the sampler activating the overriding clutch set for vertical engagement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective of the assembly of the present invention; I

FIG. 2. is a cross section of the bit attached to the coring device;

FIG. 3 is a bottom view of the bit showing the set screw in a recessed area of the bit;

FIG. 4 is a cross section of the bit taken along the line 44 of .FIG. 2;

FIG. 5 is a cross section of the bit taken along the line 55 of FIG. 2;

FIG. 6 is a view of the bit in the test hole prior to rotation showing the handle of the set screw against the wall;

FIG. 7 is a view taken along the line 77 of FIG. 6;

FIG. 8 is a view of the bit in the test hole after a quarter turn illustrating the rotation of the handle by a turn of the bit;

FIG. 9 is a view of FIG. 7 after a quarter turn of the bit showing the handle turned by the wall;

FIG. 10 is a view of the assembly, the test hole having been drilled and the ball ready to be dropped onto the check valve seat;

FIG. 1 1 is a view of the assembly, the ball check valve being constituted and the assembly ready for retrieval.

It should, of course, be understood that the description and drawings herein are illustrative merely, and that various modifications and changes can be made in the structure disclosed without departing from the spirit of the invention.

DESCRIPTION OF THE INVENTION The ball 2A is removed from the tubular coring device 2 of FIG. 1 and the bit 1 attached to the coring device by means of the set screw 13 making sure that the handle 14 is in a position of vertical to right of vertical as' shown in position A of FIG. 8. The assembly is connected to the drill pipe and lowered to drilling elevation. The drilling fluid is connected to the top of the drill pipe and drilling is started.

The initial right handed rotation of the assembly as shown by the arrow8 of FIG. 1 causes two things to happen:

First; the handle 14 of the set screw 13 is Caught by the wall 12 of FIG. 6 and rotated from position A to position B of FIG. 8. As shown in FIG. 7, the set screw lies in the space 10b formed between the recessed face 11 of the bit and the wall 12 of the drill hole. The wall 12 is formed by the circle 12 of the cutting teeth, and the bit on rotation creates the space 10b. Space 10a of FIG. 7 simply creates symmetry and prevents wobbling of the-bit on drilling. Since the set screw 13 has a left handed thread, the right handed rotation 8 releases the bit from the coring device.

The handle 14 must be in position A of FIG. 8 during the lowering to drilling elevation. In this position any contact of the handle with the wall 12 of the drill hole will result in the set screw 13 being tightened even further against the sampler 2.

. Second; the release of the bit 1 activates the overriding clutch 4 set for rotational engagement and thus the binding of the bit tothe coring device is transferred from the set screw to the clutch. The clutch consists of six clutch units spaced uniformly around the bit as .shown in FIG. 5. Each clutch unit consists of a ball bearing 16 held in place by a spring 17 in a channel 18 the channel being sealed by a plug 19.

During the drilling, drilling fluid passes down the drill pipe, down through the coring device, through the open check valve 28, around the cutting blades 5,

.around the outside of the bit 1 and back up the test hole. The cutting blades are held in position by a bolt 7 and can be removed for sharpening.

When the drilling has gone the desired distance, drilling is stopped, the drilling fluid is disconnected from the top of the drill pipe, and the ball 2A is dropped down the drill pipe coming to rest on the check valve seat 23. The relationship between the bit and the coring device is shown in FIG. with the ball 2A descending in phantom to the seat 28.

The settling of the ball 2A on the seat 28 creates the check valve 2C of FIG. 11. The test boring is now made in the usual manner. At the end of the test boring, the assembly has the arrangement shown in FIG. 11 and it is in this arrangement that the assembly is brought back to the surface.

The initial upward movement of the coring device 2 activates the overriding clutch generally denoted 20 set for vertical engagement. As shown in FIG. 4, this clutch consists of six clutch units spaced uniformly around the bit. Each clutch unit consists of a ball bearing 21 in an upwardly tapered channel22.

The working parts of the bit are protected by 0 rings 30 at the top and the bottom of the bit, the rings being made of Neoprene or a similarly resistant rubber.

While the overriding clutches in the example have been ball bearing clutches, roller bearing clutches may also be used.

I claim:

1. An earth boring bit, centrally and longitudinally apertured to accomodate a tubular coring device, the shank of the bit terminating in cutting teeth which on rotation form a drill circle said shank being in the shape of a cylinder with a flattened side and having,

e. a left handed set screw located in the flattened side, engaging the coring device and terminating in a handle which when tightened reaches to the drill circle and is in a position of vertical to right of vertical,

f. an overriding clutch means engaging the coring device on rotation and,

g. an overriding clutch means engaging the coring device on vertical movement, the elements (e), (f) and (g) to operate sequentially.

2. The bit of claim 1 wherein the shank is in the form of a cylinder with two opposing flattened sides.

3. The bit of claim 1 wherein the overriding clutch means engaging the coring device on rotation is a ball bearing overriding clutch.

4. The bit of claim 1 wherein the overriding clutch means engaging the coring device on vertical movement is a ball bearing overriding clutch. 

1. An earth boring bit, centrally and longitudinally apertured to accomodate a tubular coring device, the shank of the bit terminating in cutting teeth which on rotation form a drill circle said shank being in the shape of a cylinder with a flattened side and having, e. a left handed set screw located in the flattened side, engaging the coring device and terminating in a handle which when tightened reaches to the drill circle and is in a position of vertical to right of vertical, f. an overriding clutch means engaging the coring device on rotation and, g. an overriding clutch means engaging the coring device on vertical Movement, the elements (e), (f) and (g) to operate sequentially.
 2. The bit of claim 1 wherein the shank is in the form of a cylinder with two opposing flattened sides.
 3. The bit of claim 1 wherein the overriding clutch means engaging the coring device on rotation is a ball bearing overriding clutch.
 4. The bit of claim 1 wherein the overriding clutch means engaging the coring device on vertical movement is a ball bearing overriding clutch. 